Single band antennas typically take up significant real estate in a receiver/transmitter enclosure. With present day wireless mobile devices, there is a need to fit multiple antennas in approximately the same space previously occupied by a single antenna. Where two different frequency bands, and therefore two antennas are needed, if a difference in the center frequencies of two antennas is more than an octave (the higher frequency is twice the lower frequency), there is a need for two separate antennas, one for each receiver/transmitter. This will increase even more the space requirement in an enclosure. Unfortunately, related art antenna structures for mobile devices cannot fit two antennas operating in different frequency bands in the same enclosure.